In the domain of wine containers, different types of plugs are used to seal bottles containing wine that are sold on the market.
It is known for many decades to plug wine and spirit bottles by means of a cylindrical cork stopper which is pressed in the neck of the bottle with a certain compression rate. Although this technique has been used exclusively for a very long time, in recent years the cork stopper was called into question again for various reasons linked mainly to the cost and the quality of the stored wine, in particular the development of the so-called “cork” taste.
Compressible stoppers made of synthetic material were developed as replacements for wine bottle cork stoppers and are being used more and more. These compressible synthetic stoppers are considered neutral relative to the bottled wine, and their cost is easier kept under control than that of cork stoppers. However, they have the disadvantage of having low or no recyclability and are not always being easy to extract. These synthetic stoppers also may evoke an image with consumers of industrial production and low quality.
It is also known that wine bottles can be plugged with screw caps. This plugging technique can be well controlled and the preservation performance is considered similar to that of cork or synthetic stoppers. Furthermore, screw caps are recyclable, at least in theory, after separating the internal liner from the cap. However, especially in Europe, this plugging technique may still be considered reserved for low range wines and wines from the so-called New World.
Document EP-A-0 027 780 proposes a variety of bottles in particular for sparkling beverages, e.g. ciders or champagne. These bottles are provided with several internal grooves or ribs in the neck and can be opened after having removed a wire mesh which is crimped around neck and stopper. However, it seems that the beverages are not perfectly sealed by the co-operation of the bottle neck and the cork as described in EP-A-0 027 780, at least in some of the bottles, shown therein, because the internal grooves or ribs in the neck are forming tracks in the stopper along which gas and liquid can escape to the exterior. In one of the bottles of EP-A-0 027 780, the internal diameter of significantly increases at the lower end of the cork, i.e. is not cylindrical. Correspondingly the diameter of the cork significantly increases to the lower end (typically about a factor of two). Having such a non cylindrical cork stopper is typical for champagne bottles to increase the holding forces of the cork. Furthermore, the compression rate of champagne corks is typically rather high. Therefore, such bottles cannot be closed anymore by hand using the same cork. Nevertheless, when pressurized beverages are plugged, a wire mesh is additionally used to hold the stopper in place once the bottle is plugged to avoid unplugging due to the gas pressure inside the bottle. On the other hand, when the mesh is removed, unplugging of a bottle with a pressurized beverage is usually facilitated with the aid of the internal pressure of the beverage, such that e.g. a champagne cork can be extracted anyway by hand already without grooves or ribs in the neck. However, the applicable forces and sealing requirements are largely different between bottling pressurized beverages on the one hand side and wine or spirits on the other hand side.
In GB 132,589, U.S. Pat. No. 2,215,984, DE 183525, U.S. Pat. No. 1,406,722, FR 697,986, U.S. Pat. No. 1,560,158, BE 488693 equipment and processes for producing threaded containers are proposed. However, the containers produced by these processes are single-threaded with fine pitch and several revolutions and are therefore, cumbersome to open and to close.
It is an object of the present invention to provide a glass container, specifically a glass bottle for holding wine or spirits, which allows reversible and easy unplugging and plugging, without the negative image attached to a screw cap.
Another object of the invention is to provide a glass container for wine or spirits that retains plugging by a cork stopper, while allowing reversible and easy unplugging and plugging of non-pressurized beverages like wine and spirits by screwing and unscrewing of a cork with an essentially cylindrical plugging portion.
Another object of the invention is to provide a glass container with an internally cylindrical neck for bottling wine or spirits by a cork stopper with a cylindrical plugging portion that still guarantees good sealing and preservation of the wine or spirit, without excessive cork compression and without using an external holding device such as a wire mesh.
The objects of the invention are achieved by subject matter of claim 1. Preferred embodiments are defined in the dependent claims.
According to an aspect of the invention a glass container, specifically a bottle for storing non-pressurized beverages, e.g. a wine or spirit bottle is provided.
The container has a neck which is suitable for sealing the container with a compressible stopper having a plugging portion of cylindrical form. The neck defines a longitudinal axis and comprises an upper circular opening or finish and an internal thread which allows for reversible opening and closing of the container by unscrewing and screwing of said compressible stopper, respectively. The neck comprises an internal wall forming a straight cylindrical section, which extends from the opening over a height of at least 30 mm along the longitudinal axis.
The internal thread of the neck comprises at least two independent thread turns in the internal wall which are formed as ribs protruding from the internal wall starting at different angular positions around said longitudinal axis and being positioned in said straight cylindrical section, thereby forming a threaded section of internally cylindrical form. Furthermore, the neck comprises a first thread-free sealing section which is positioned beneath the threaded section, i.e. beneath a lower end of the thread turns, but still within said straight cylindrical section. Therewith, the straight cylindrical section is divided in at least two subsections, namely the threaded section defining said internal thread and the first thread-free sealing section, wherein both, the threaded section and the first thread-free sealing section are of internally cylindrical form and extend coaxial with the longitudinal axis of the neck.
Preferably, the first thread-free sealing section of internally cylindrical form extends beneath the threaded section from a lower end of the thread turns downwardly over a height of at least 5 mm, preferably over a height of at least 10 mm. Thus, the straight cylindrical section extends from the lower end of the thread turns downwardly over a height of at least 5 mm, preferably over a height of at least 10 mm along the longitudinal axis, thereby forming the first thread-free sealing section beneath the threaded section and being of cylindrical form.
That is, a first internally straight cylindrical and thread-free sealing ring of the internal wall of the neck with constant diameter is formed beneath the thread turns, so that a cylindrical stopper screwed in the bottle neck will totally conform to the plain thread free cylindrical surface beneath the thread turns, resulting in an improvement of preventing liquid leakage and passage of air from the exterior to the liquid along the thread turns at a moderate compression rate of a cork stopper.
The compressible stopper has a plugging portion of cylindrical form which extends beneath the threaded section into the first thread-free sealing section when being fully inserted in the neck of the glass container. Then the cylindrical plugging portion of the stopper is in full circumferential thread-free sealing contact with the internal wall of the neck over a height of at least 5 mm, preferably over a height of at least 10 mm, in the internally cylindrical first thread-free sealing section.
Further to improve the sealing capabilities of the container with inserted stopper, the straight cylindrical section of the internal wall of the neck is extending by preference also from the upper circular opening of the neck to the upper end of the thread turns over a height of at least 2 mm, preferably over a height of between 2 mm and 5 mm, thereby forming an second cylindrical thread-free sealing section between the upper circular opening and the threaded section. Therewith, a second internally straight cylindrical and thread-free ring of the internal wall of the neck is provided with constant diameter above the thread turns, so that the cylindrical plugging portion screwed in the bottle neck will be in full circumferential thread-free sealing contact with the internal wall above the thread turns. In other words, above the screw thread turns of the neck there is a second internally straight cylindrical and thread-free sealing ring with a diameter greater than the free diameter of the threaded section, and where a stopper will totally circularly conform to the wall when it is introduced in the neck to seal the container.
By preference, the thread turns extend over a height of at least 5 mm, but preferably not more than 20 mm, more preferably over a height of 10 mm±5 mm. In any case the turns extend preferably entirely within the straight cylindrical section. This geometry advantageously results in a good combination between holding/sealing properties and easy opening and closing of a wine or spirit bottle.
Preferably the straight cylindrical section has an internal diameter defined by the internal wall, wherein the internal diameter is selected within an interval of 18 mm to 21 mm. The neck has an outer diameter of between 26.5 mm and 28.5 mm at a position of 40 mm beneath the opening, which is advantageously slender.
Preferably the internal thread consists of between 3 and 5 independent thread turns. The thread turns are independently starting and ending at different angular positions, i.e. are staggered around the longitudinal axis, are straight and extend parallel to each other. Furthermore, the thread turns of the internal thread are identical and distributed at regular azimuthal angular intervals over the internal wall of the neck, in particular are staggered by an azimuthal angle of 360°/m, where m is the number of independent thread turns.
According to a preferred embodiment of the invention, the thread turns of the internal thread have a constant pitch angle of between 30° and 50°, preferably 37°±5°.
The ribs protruding from the internal wall and forming the thread turns have a preferred radial thickness between 0.2 mm and 3 mm, preferably a base width of between about 0.5 mm and 3 mm at the internal wall and preferably an essentially constant cross section.
Preferably the thread turns extend around the longitudinal axis over an azimuth angle of between 45° and 180°, more preferably of 90°±30°.
In, particular, such glass container allows plugging and unplugging by manual rotation of the stopper over an angle of less than 180° with modest effort. Preferably, a cork stopper with a cylindrical plugging portion and a head of larger diameter than the plugging portion is used, such that the user can grasp the head for unscrewing and screwing.
In this context, “cork stopper” includes any stopper made from natural rough or agglomerated cork. Nevertheless, agglomerated cork may be preferred for implementation of the invention. However the invention is not limited to the exclusive use of cork stoppers.
The neck geometry advantageously avoids the stored liquid from disturbingly penetrating into the thread turns while at the same time allowing the stopper to be self-holding without the need of an external fixing device like a wire mesh on the one hand side and to be manually reversibly unscrewable and screwable on the other hand side, both at a moderate compression rate of the stopper and without the aid of pressure inside the container when first opening the container. That is, this kind of plugging solution seals the container hermetically while providing great ease and practicality for the user, who can indefinitely open and close the container by a simple manual operation of screwing and unscrewing the stopper in the neck of the container. Furthermore, the container provides good sealing of the stopper both before and after the first opening of the container and for several consecutive openings thereafter, which turned out to be difficult to achieve with a screw cork stopper integrated in the neck of a wine or spirit bottle.
Furthermore, this kind of plugging solution preserves the high range image of the product held in the container when using a natural cork stopper while retaining the advantages of a metallic or plastic screw cap.
The use of cork stoppers is preferred in association with the container of the invention, because of its perfect recyclability and the growing character of cork commerce.
The bottle is preferably produced with a blow-and-blow process.
Various other characteristics will result from the following description with reference to the attached drawings which show non-limiting examples wherein same and similar elements are denoted with the same reference signs.